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Dicamba may be an efficacious option for the control of glyphosate-resistant (GR) horseweed in glyphosate/dicamba-resistant soybean; research is needed to optimize the application rate based on horseweed height at the time of application. The purpose of this study was to determine the effect of glyphosate/dicamba rate and application timing for the control of GR horseweed. Glyphosate/dicamba was applied at three rates (900, 1,350, and 1,800 g ae ha−1) at three horseweed application timings (5, 15, and 25 cm) in a factorial design. There was no interaction between glyphosate/dicamba rate and timing for GR horseweed control or soybean yield; however, there was an interaction for GR horseweed density and biomass. At 2 and 4 wk after application (WAA), there was a decrease in GR horseweed control as the height at the time application increased. At 4 WAA, the application of glyphosate/dicamba to GR horseweed that was 5-, 15-, and 25-cm tall provided 87%, 76%, and 62% control, respectively. There was no impact of glyphosate/dicamba application timing on soybean yield. At 2, 4, and 8 WAA, there was an increase in GR horseweed control as the rate of glyphosate/dicamba was increased. At 8 WAA, glyphosate/dicamba applied at 900, 1,350, and 1,800 g ae ha−1 controlled GR horseweed 76%, 87%, and 92%, respectively. Earlier application timings and higher rates of glyphosate/dicamba caused the greatest reduction in GR horseweed density and biomass. Reduced GR horseweed competition resulted in a 100% to 144% increase in soybean yield, but there was no difference in soybean yield among glyphosate/dicamba rates tested.

Introduction: In the past few years, there has been an increase in awareness of the challenge of managing work related stress in EMS. Extant research has liked different types of chronic and critical incident stress to stress reactions like posttraumatic stress. However, there is no tool to capture the transactional stresses which are associated with the day to day provision of service (e.g., dealing with offload delays or mandatory overtime) and interacting with allied professions (e.g., emergency department staff) or allied agencies (e.g., law enforcement). The purpose of this study was to develop and validate a measure which captured transactional stresses in paramedics Methods: An online survey was conducted with ten Canadian Paramedic Services with a 40.5% response rate (n= 717). Factor analysis was used to identify variation in responses related to the latent factor of transactional stress. The scale was validated using both exploratory and confirmatory factor analyses. Results: The sample of transactional stress questions was split to allow for multiple analyses (EFA n=360/ CFA n=357). In the exploratory factor analysis, principal axis factoring with an oblique rotation revealed a two-factor, twelve item solution, (KMO=.832, x2=1440.19, df=66, p<.001). Confirmatory factor analysis also endorsed a two factor, 12 item solution, (x2 =130.39, df=51, p<.001, CFI=.95, TLI= .93, RMSEA= .07, SRMR= .06). Results supported two groups of six-item factors that captured transactional stress in the provision of service. The factors, clearly aligned with transactional stress issues internal to the ambulance and transactional stress relationships external to the ambulance. Both subscales demonstrated good internal reliability (= .843/ =.768) and were correlated (p.01) with a convergent validity measure. Conclusion: This study successfully validated a two-factor scale which captures stress associated with the day to day provision of EMS and the interaction with allied professions. The development of this measure of transactional stresses further expands the potential that paramedics, Paramedic Services, employers, and prehospital physicians may understand the dynamics that influence provider health and safety. As a result, there may be greater opportunities to intervene holistically to improve paramedic health and well-being.

From Neolithic Malta, there is evidence of increasing population size accompanied by increasingly elaborate material culture, including the famous megalithic architecture. Stoddart et al. (1993) argued that social tensions and controls increased as food resources diminished. One important requirement of this argument is that the Neolithic inhabitants of Malta depended entirely on domesticated plants and animals for subsistence and therefore, with increased population sizes, the poor agricultural potential of these islands was stretched. However, it is possible that the consumption of wild foods, particularly marine resources, in the Neolithic would make up any shortfall in the agricultural foods. A direct way of measuring the amounts of marine protein in human diets is through chemical analysis of human bone. Stable isotope analyses undertaken on seven Accelerator Mass Spectrometer (AMS) radiocarbon dated humans from the Neolithic at the Brochtorff Circle indicated that there is no evidence for the significant use of marine foods by these Neolithic individuals. These new data indicate that agricultural foods were the dietary staple for this sample of the Maltese Neolithic population and therefore support the argument that increasing population during the Neolithic could have resulted in increasing resource stress.

We describe the operation of a commercial system as modified for preparation of CO2 for the CO2 source. AMS samples are automatically combusted in a CHN analyzer, and stable isotope measurements are made on line. We describe the performance of this equipment, with reference to yield, sample contamination, memory effect, accuracy of isotope measurement, convenience and cost. We discuss the current status of dating using the CO2 source. This is the only source in operation at Oxford, and has been in routine dating since September 1989. We assess the practicalities of operation, including the latest measurements on background, memory, sample-size requirements and operating schedules. We also describe modifications to the sputter beam optics and to the gas handling systems.

Since Middleton showed the potential for a sputter source working from CO2, we have been building a source which can automatically change samples. The source produces a maximum beam of 25μA of C−, with typical operation between 10 and 20μA. Although beam generation from the source is very reliable, the mechanics of sample changing have given considerable problems. The changing of samples also involves considerable care in gas handling, and a computer control system has been written which ensures the correct sequence of the 16 operations required for sample change.

A previous radiocarbon dating and stable isotope study of directly associated ungulate and human bone samples from Late Mesolithic burials at Schela Cladovei in Romania established that there is a freshwater reservoir effect of approximately 500 yr in the Iron Gates reach of the Danube River valley in southeast Europe. Using the δ15N values as an indicator of the percentage of freshwater protein in the human diet, the 14C data for 24 skeletons from the site of Lepenski Vir were corrected for this reservoir effect. The results of the paired 14C and stable isotope measurements provide evidence of substantial dietary change over the period from about 9000 BP to about 300 BP. The data from the Early Mesolithic to the Chalcolithic are consistent with a 2-component dietary system, where the linear plot of isotopic values reflects mixing between the 2 end-members to differing degrees. Typically, the individuals of Mesolithic age have much heavier δ15N signals and slightly heavier δ13C, while individuals of Early Neolithic and Chalcolithic age have lighter δ15N and δ13C values. Contrary to our earlier suggestion, there is no evidence of a substantial population that had a transitional diet midway between those that were characteristic of the Mesolithic and Neolithic. However, several individuals with “Final Mesolithic” 14C ages show δ15N and δ13C values that are similar to the Neolithic dietary pattern. Provisionally, these are interpreted either as incomers who originated in early farming communities outside the Iron Gates region or as indigenous individuals representing the earliest Neolithic of the Iron Gates. The results from Roman and Medieval age burials show a deviation from the linear function, suggesting the presence of a new major dietary component containing isotopically heavier carbon. This is interpreted as a consequence of the introduction of millet into the human food chain.

Human bones from single inhumation burials and artifacts made from terrestrial mammal (ungulate) bone found in direct association with the skeletons were obtained from the Stone Age site of Schela Cladovei situated just below the Iron Gates Gorge of the River Danube. The results of stable isotope analyses of the human bone collagen are consistent with a heavy dependence on aquatic protein while radiocarbon dating of the samples reveals an offset of 300–500 years between the two sample types, indicating a freshwater reservoir effect in the human bone samples. Since protein consumption is by far the major source of nitrogen in the human diet we have assumed a linear relationship between δ15N and the level of aquatic protein in each individual's diet and derived a calibration for 14C age offset versus δ15N which has been applied to a series of results from the site at Lepenski Vir within the gorge. The corrected 14C ages (7310-6720 BP) are now consistent with the previous 14C age measurements made on charcoal from related contexts (7360–6560 BP). In addition, the data indicate a change from a primarily aquatic to a mixed terrestrial/aquatic diet around 7100 BP and this may be argued as supporting a shift from Mesolithic to Neolithic. This study also has wider implications for the accurate dating of human bone samples when the possibility exists of an aquatic component in the dietary protein and strongly implies that δ15N analysis should be undertaken routinely when dating human bones.

We have developed and demonstrated a practical methodology for dating specific compounds (and octade-canoic or stearic acid—C18:0—in particular) from the lipid material surviving in archaeological cooking pots. Such compounds may be extracted from about 10 g of cooking potsherd, and, after derivatization, can be purified by gas chromatography. To obtain sufficient material for precise dating repetitive, accumulating, GC separation is necessary. Throughout the 6000-year period studied, and over a variety of site environments within England, dates on C18:0 show no apparent systematic error, but do have a greater variability than can be explained by the errors due to the separation chemistry and measurement process alone. This variability is as yet unexplained. Dates on C16:0 show greater variability and a systematic error of approximately 100-150 years too young, and it is possible that this is due to contamination from the burial environment. Further work should clarify this.

The prehistoric settlement of Abu Hureyra in Syria was occupied in both the Epipaleolithic and Neolithic periods. It has provided significant evidence for changes in economy at the time of the inception of agriculture in southwest Asia. Twenty accelerator mass spectrometry (AMS) dates have been obtained to determine the duration of occupation of the Epipaleolithic settlement there and the precise age of samples of cereal grains and animal bones found within it. The results have demonstrated that the AMS technique can answer such questions because it dates exceedingly small samples with high precision. The dates indicate that the Epipaleolithic settlement was inhabited for about a millennium, from before 11,000 to nearly 10,000 bp, significantly longer than had been anticipated from study of the artifacts.

We have AMS dated samples of Pacific rat (Rattus exulans) bone “collagen” and filtered gelatin samples from the prehistoric site of Shag River Mouth, New Zealand. The age of occupation of this site has previously been determined based on 50 radiocarbon measurements. The site dates to the late Archaic phase of southern New Zealand prehistory (about 650–500 BP; 14th–15th century AD). The results of rat bones which we have dated produce a range in ages, from about 980–480 BP, a difference we attribute to a combination of effects. Pretreatment appears to be an important variable, with results showing differences in 14C age between the progressive “collagen” and filtered gelatin chemical treatment stages. Amino acid profiles suggest there is a proteinaceous but non-collagenous contaminant which is removed by the more rigorous pretreatment. Stable isotopes vary between pretreatments, supporting the removal of a contaminant, or contaminants. Variation in δ15N values imply a range in uptake of dietary protein, and might suggest a potential influence from the local aquatic environment or the consumption of marine-derived protein. Rats are opportunistic, omnivorous mammals, and, therefore, obtain carbon from a variety of reservoirs and so we ought to expect that in environments where there is a variety of reservoirs, these will be exploited. Taken together, the results show that rat bone AMS 14C determinations vary in comparison with the established age of the site, but are in notably better agreement with non-collagenous data than in previously published determinations (Anderson 1996).

We present the results of 18 radiocarbon determinations on the carbonate fraction of tooth enamel prepared from nine separate teeth. The known ages of the teeth vary from 11 to >200 ka bp, and are from three sites. The sample preparation procedures varied somewhat, but were broadly based on procedures found to give satisfactory results on carbon stable isotope measurements. All the 14C dates obtained are too young, by an equivalent contamination of ca. 6% Modern (pMC). This value is fairly consistent despite variations in sample preparation. We discuss the implications for using enamel as a possible alternative to bone when insufficient collagen is available.

Preliminary experiments were carried out on archaeological wood to investigate methods of cellulose hydrolysis and carbohydrate monomer purification for the purpose of compound-specific radiocarbon dating. The Chelford log, a known 14C dead source of wood cellulose, was selected for study in order to investigate the levels of contamination introduced during sample purification. Two methods of hydrolysis were examined, mineral acid hydrolysis and enzyme hydrolysis using cellulase from Penicillium funiculosum. Under the conditions described, enzymolysis was far superior to acid hydrolysis in terms of the glucose monomer yield. Glucose monomer purification was accomplished using high pH anion exchange chromatography with pulsed amperometric detection. This high performance liquid chromatography (HPLC) method does not require sample derivatization and the chromatography products can be collected in water. These characteristics make it potentially well suited to carbon dating applications. 14C dating of chromatographically purified glucose fractions revealed significant levels of contamination had accumulated during both protocols. Glucose contamination from the cellulase enzyme preparation was a major source of contamination within the enzymatically hydrolyzed samples. Ultrafiltration of the enzyme removed some but not all of this contamination. The contamination must be reduced 10-fold before the methodology could be viable for dating. This hydrolysis/HPLC method is also being investigated for 14C dating of other carbohydrate polymers such as chitin.

The Labiatae of SW Asia arc analysed. There is a major development of the family in this area with c. 1100 species, much morphological diversity, many illuminating distribution patterns and very high endemism levels; species endemism averages over 70% in the medium-sized and large genera. Areas of high concentrations of endemic taxa are indicated. The very significant differences between the Labiate floras of Turkey, Iran and Afghanistan throw doubt on designating all the steppic part of the area as Irano-Turanian; there is a strong Mediterranean floristic connection throughout much of Turkey and little evidence of Irano-Turanian influence. There are numerous taxonomically very isolated genera and species; some of these genera have very restricted distributions, a few are almost cosmopolitan.

The Aurignacian, traditionally regarded as marking the beginnings of Sapiens in Europe, is notoriously hard to date, being almost out of reach of radiocarbon. Here the authors return to the stratified sequence in the Franchthi Cave, chronicle its lithic and shell ornament industries and, by dating humanly-modified material, show that Franchthi was occupied either side of the Campagnian Ignimbrite super-eruption around 40000 years ago. Along with other results, this means that groups of Early Upper Palaeolithic people were active outside the Danube corridor and Western Europe, and probably in contact with each other over long distances.

Since the aminoglycoside antibiotic apramycin was licensed for veterinary use in 1980, all isolates of Escherichia coli and salmonellas received at the Central Veterinary Laboratory have been monitored for resistance to apramycin and the related antibiotic gentamicin. During the period 1982–4, the incidence of resistance in E. coli to apramycin increased from 0·6% in 1982 to 2·6% in 1984. In salmonellas the incidence of resistance to apramycin increased from 0·1% in 1982 to 1·4% in 1984. Resistance to both apramycin and gentamicin was detected in six different salmonella serotypes, although an isolate of Salmonella thompsonfrom poultry was resistant to gentamicin but not apramycin. Most of the cultures were isolated from pigs, although the incidence of apramycin resistance in S. typhimurium (DT 204C) from calves has shown a recent dramatic increase. All the isolates with one exception produced the enzyme aminoglycoside 3-N-acetyltransferase IV (ACC(3)IV). The resistance was transferable by conjugation in most of the strains examined, and the plasmids specifying the resistance have been found to belong to a number of different incompatibility groups. Plasmids from three E. coli strains were compatible with all the reference plasmids and belonged to a previously undescribed group which was investigated further.

It is suggested that bacteria from humans should be examined for resistance to apramycin and gentamicin to determine the possibility of the antibiotic-resistance bacteria, and their genes, spreading from animals to humans.

Techniques for identifying organic residues in pottery have been refined over the years by Professor Evershed and his colleagues. Here they address the problem of radiocarbon dating these residues by accelerator mass spectrometry (AMS) which in turn dates the use of the pot. Fatty acids from carcass and dairy products cooked in the pot were isolated from early Neolithic carinated bowls found at the Sweet Track, Somerset Levels, England, and then dated by AMS. The results were very consistent and gave an excellent match to the dendrochronological date of the trackway. The method has wide potential for the precise dating of pottery use on sites.

Analysis of global gene expression in immune cells has provided unique insights into immune system function and response to infection. Recently, we applied microarray and serial analysis of gene expression (SAGE) techniques to the study of γδ T-cell function in humans and cattle. The intent of this review is to summarize the knowledge gained since our original comprehensive studies of bovine γδ T-cell subsets. More recently, we have characterized the effects of mucosal infection or treatment with microbial products or mitogens on gene expression patterns in sorted γδ and αβ T-cells. These studies provided new insights into the function of bovine γδ T-cells and led to a model in which response to pathogen-associated molecular patterns (PAMPs) induces ‘priming’ of γδ T-cells, resulting in more robust responses to downstream cytokine and/or antigen signals. PAMP primed γδ T-cells are defined by up-regulation of a select number of cytokines, including MIP1α and MIP1β, and by antigens such as surface IL2 receptor α (IL-2Rα) and CD69, in the absence of a prototypic marker for an activated γδ T-cell, IFN-γ. Furthermore, PAMP primed γδ T-cells are more capable of proliferation in response to IL-2 or IL-15 in the absence of antigen. PAMPs such as endotoxin, peptidoglycan and β-glucan are effective γδ T-cell priming agents, but the most potent antigen-independent priming agonists defined to date are condensed oligomeric tannins produced by some plants.

It is widely recognized that when marine resources form a significant proportion of the human diet, this results in radiocarbon ages for human remains that are significantly older than the contemporary atmosphere. While there has been widespread assessment of marine 14C reservoir ages, there has been little study of the freshwater equivalent. However, recent analyses of human bone from archaeological sites in the Danube Valley have confirmed the existence of a large freshwater 14C reservoir effect.